1. Field of the Invention
The present invention relates to a flat panel display device and fabrication method thereof.
2. Background of the Related Art
An insulating layer is essential for fabricating a flat panel device.
In flat panel displays, an organic EL (electroluminescent) device emits a light in a manner that electric charges are injected into an organic layer between an electron injection electrode (cathode) and a hole injection electrode (anode), electrons and holes are paired, and the resulting pairs emit light. The EL device is driven by a low voltage and consumes less power.
In this case, an insulating layer is formed on a substrate so as to cover the edges of the anode which are vulnerable during the fabrication process.
When the edges of the anode are damaged, the cathode and anode are easily shorted. Once the cathode and anode are shorted, the organic layer between the cathode and anode is damaged. Thus, the ELD device fails to emit light normally.
Insulating layers are mainly divided into inorganic insulating layers and organic insulating layers. The inorganic insulating layers include oxide, nitride and the like, while the organic insulating layers include polyimide, polyacryl, photoresist and the like.
However, the use of inorganic insulating layers requires highly expensive equipment. Therefore, organic insulating layers have greater merit using a conventional PR (photoresist) line for fabrication.
An organic insulating layer in a display device is formed on glass or ITO (indium tin oxide). Namely, patterns of the organic insulating layer are defined on the glass including the patterned ITO. The ITO includes auxiliary electrodes such as a bus electrode and the like.
Such a process, as shown in FIG. 1 and FIG. 2, of defining an organic insulating pattern results in disadvantages. Most organic insulating layers have excellent adhesion to ITO but poor adhesion to glass. When organic insulating layer patterns are developed, the patterns at the ITO side remain intact but those at the glass side peel off
As mentioned in the above explanation, a flat panel device according to the related art brings about problems/disadvantages such as residues of an organic insulating layer during a patterning process, poor shapes of inorganic insulating layer patterns, and the like, thereby degrading characteristics such as device performance, endurance and the like.